requestAssociation with empty file extension string {""} throws StringIndexOutOfBoundsException
java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(Unknown Source)
at com.sun.deploy.association.utility.AppUtility.addDotToFileExtension(Unknown Source)
at com.sun.deploy.association.Association.addFileExtension(Unknown Source)
at com.sun.jnlp.IntegrationServiceImpl.hasAssociation(Unknown Source)

Here again we may need throw either IllegalArgumentException or should not create any association with file extension should not throw this Runtime Exception.
                IntegrationService is = (IntegrationService)
                        ServiceManager.lookup("javax.jnlp.IntegrationService");
                String mime = "abc/xyz";
                String [] exts = {""};
                boolean result = is.requestAssociation(mime,exts);